Brachial Artery t-PA Release in Heart Transplant Recipients

Vanderbilt University

Overview

Bradykinin stimulates t-PA release from intact vessels, but not from endothelial cells in culture. It has been proposed that the nerves of blood vessels are the source of bradykinin stimulated t-PA release. In order tho test this hypothesis, we intend to infuse bradykinin into the brachial (arm) artery and the coronary arteries of heart transplant recipients and control subjects. This is because heart transplant recipients do not have nerves to their coronary arteries. This protocol studies the effects of bradykinin on t-PA release in the forearm of transplant recipients. The brachial artery has intact nerves. Separate protocols address coronary artery infusions in healthy subjects and transplant recipients and forearm infusions in healthy subjects.

Study Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

NONE

Conditions

Heart Transplantation

Interventions

BradykininDRUG

Patients receive 0, 10, 20, and 40 ng/100cc forearm volume/min of bradykinin intrabrachial.

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion criteria: 1. Adults 18 years and greater who have undergone heart transplantation 2. Healthy Exclusion criteria: 1. PVC \< 30 2. Hypertensive subjects on ACE inhibitors 3. Pregnant or nursing mothers 4. Diabetic with HbA1C \> 7.5 or stigmata of end organ damage (neuropathy, retinopathy, nephropathy, cardiomyopathy) 5. Cholesterol \> 30 mg/dL above NCEP accepted level based on cardiac risk. 6. Triglycerides \> 200 7. Previously diagnosed obstructive coronary artery disease 8. Renal insufficiency (Creatinine ≥ 1.5 mg/dl) 9. History of cerebrovascular disease 10. Any chronic inflammatory disease (rheumatologic, inflammatory bowel disease, etc) 11. Uncontrolled Stage 2 Hypertension (160/100 mmHg), or end organ damage due to hypertension (left ventricular hypertrophy, atrial fibrillation, hematuria, renal insufficiency, prior cerebrovascular disease). 12. Angiotensin converting enzyme inhibitor use 13. Coagulopathy (INR ≥ 1.5, PTT ≥ 150% of control) 14. Peripheral Vascular Disease 15. Other chronic medical illnesses at the discretion of the investigators

Locations (1)

Vanderbilt University Medical Center

Nashville, Tennessee, United States

Outcomes

Primary Outcomes

Peak t-PA release

Time frame: Single Study Visit

Secondary Outcomes

t-PA release at various doses

Time frame: Single Study Visit

Data from ClinicalTrials.gov

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